In this study, the effect of non-ionizing radiation on the integrity of mature spermatocytes was examined. Semen was obtained from 10-month-old turkeys and diluted to a concentration of 3.5 X 10 to the 8 sperm/ml using Beltsville Poultry Semen Extender. The sperm were exposed for 30 minutes to 2.45 GHz microwave radiation at specific absorption rates (SAR's) of 0, (sham) 10 or 50 mW/g. The waveguide exposure system maintained the control (non-irradiated) and irradiated samples at about 40C throughout the experiment. Microwave radiation did not alter membrane permeability to a vital stain or the intracellular enzymes LDH and GOT. The in vivo performance of the sperm following in vitro irradiation was also examined. The fertility of virgin turkey hens given a single insemination of microwave exposed sperm was similar for the 10 mW/g and nonexposed sperm. Hatchability and embryonic mortality were not different among the treatment groups. A number of hematological parameters in the progeny of the turkey hens are now being examined.